A core network in a system architecture evolution (SAE) network mainly includes three logical functionalities: a mobility management entity (MME), a serving gateway (SGW), and a packet data network (PDN) gateway, PGW for short.
The MME is responsible for functions such as non-access stratum (NAS) signaling transmission, NAS signaling encryption, roaming, tracking, temporary user identity allocation, and security. The SGW is responsible for functions such as a local mobility anchor, a mobility anchor within a 3rd Generation Partnership Project (3GPP) system, and lawful interception of related information. The PGW is responsible for related functions such as policy execution, charging, and lawful interception.
The SAE network may further include an HSS, a PCRF, and the like. The home subscriber server (HSS) is configured to store subscriber subscription information. The policy and charging rules function (PCRF) is a functional entity in a policy and charging control (PCC) architecture, and is configured to set a policy and charging rule for a service flow in a network. The policy and charging rule includes a Quality of Service (QoS) rule, and the like.
In addition, the PCC architecture may further include a policy and charging enforcement function (PCEF), which is configured to complete a policy and charging enforcement function. The functional entity is usually jointly deployed with the PGW. The PCC architecture may further include a subscription profile repository (SPR), which is a database storing a parameter of a service data flow of a subscriber.
To open related information of a 3GPP network to a 3rd party application (3rd Application) server, the prior art provides an enhanced network architecture. That is, a logical functional entity—a service capability exposure function (SCEF) is introduced. There is an interface between this logical function and a network element device in the SAE network. An upper layer of the SCEF is an application layer, that is, the 3rd party application server (AS). The 3rd party application server may establish a connection to the SCEF, so that the 3GPP network may send information to the 3rd party application server by using the SCEF, and the 3rd party application server may also send information to the 3GPP network by using the SCEF.
In this enhanced network architecture, related information transmitted during execution of charging or another policy for a data flow is transmitted among the AS, the SCEF, and the PCRF on a per user equipment (UE) basis. A relatively large amount of the related information of charging and another policy results in relatively heavy load of information transferred on the interface of the SCEF. Particularly, if related information of charging and another policy corresponding to UE frequently changes, the related information of charging and another policy needs to be frequently transmitted on the interface.